Arnold had previously revealed that the process involved in securing overage Socceroos for the Tokyo 2021 Olympic Games had been a "50-50" gamble, but he's now revealed just how hard it was to secure spots.

The Olyroos will only take two overage players to Tokyo 2021, Ruon Tongyik and Mitch Duke, both of whom play in the A-League. Tongyik is only over the Olympics' age eligibility by three days.

"This is probably one of the most complicated processes I've ever been through to select the squad," Arnold told AAP.

"I probably made 30 to 40 phone calls to clubs for over-age players to see which players could get released. Pretty much out of 30-40, came back three (positive)."

"We looked at that as Socceroos is priority number one for the third phase (of World Cup qualifying)," Arnold said.

"I always stated and, I mean this, that I wasn't going to build a squad around three over-age players, it's more about filling spaces, if we need."

In addition to lacking the likes of established Socceroos stars Mat Leckie, Tom Rogic, Aaron Mooy and Ajdin Hrustic, there are a few high profile absences from the Olyroos Olympic squad from the eligible age group.

Melbourne City trio Aiden O'Neill, Marco Tilio and Stefan Colakovski also miss out, as does Brisbane Roar striker Dylan Wenzel-Halls.

In the foreign ranks, VfB Stuttgart's Alou Kuol, Borussia Monchengladbach's Jacob Italiano, Fulham's Tyrese Francois, Crystal Palace's Jay-Rich Baghuelou, and Croatian-based Aussies Deni Juric and Anthony Kalik all miss out on spots.

This is despite most of them playing in the Olyroos' recent friendly series, which occurred during a FIFA international break.

But arguably the biggest Australian star under 24-years-old, Stoke City's Harry Souttar, will be at the games and Arnold praised Stoke for allowing him to play.

"They want what's best for Harry, the player, they know how much Harry wants to play for Australia," he said.

"He's a kid that bangs on the manager's door and says 'I want to do this and I want to go to the Olympics' and makes it clear that it'd be better for him in the long run, and Stoke City."

PLUS...

Chosen! The Olyroos best starting XI for Tokyo Olympics

The waiting and speculation are over. Arnie’s Olyroos have been selected so the debate turns now from who should be in the 18 to who should be in the 11 for the Tokyo 2021 Olympic Games.

PLUS...

Biggest exclusions from the Olyroos Tokyo Olympics squad

The Olyroos squad for the Tokyo 2021 Olympic Games has been named and the team features some big omissions, so let’s see who didn’t make the cut.

PLUS...

Newcastle sign Wellington A-League star as Papas plans more signings

A-League club Newcastle Jets have signed Wellington Phoenix star Cameron Devlin as new coach Arthur Papas plots a reinvigoration of last season's cellar dwellers.

PLUS...

Adelaide cut four A-League players, sign up two NPL guns

Adelaide United have parted ways with four A-League players but have signed two NPL stars to scholarship contracts.

PLUS...

'You have to go higher': Aussie coach on fire in Japan with Postecoglou playbook

Former Ange Postecoglou assistant Peter Cklamovski is doing an incredible job at J2 League side Montedio Yamagata, guiding a stunning turnaround at the former strugglers.